基于苯甲羟肟酸的三元组合捕收剂高效浮选白钨矿研究及分子动力学模拟

Research and Molecular Dynamics Simulation of Efficient Flotation of Scheelite with Ternary Combined Collector Based on BHA

羟肟酸是常见的白钨矿浮选捕收剂,由于其价格高、用量大导致浮选成本偏高。为实现白钨矿的低成本高效浮选,提出一种降本增效的白钨矿浮选三元组合捕收剂:苯甲羟肟酸(BHA)+R-苯甲酸(4-MBA)+辛基羟肟酸(OHA)。采用分子动力学模拟计算方法证实了该组合捕收剂在白钨矿浮选体系中存在协同作用;同时,通过实际矿石浮选实验,进一步验证了组合捕收剂对白钨矿有着良好的捕收性能。分子动力学模拟结果表明,随着捕收剂种类的增加,白钨矿(112)表面水分子相对浓度也随之降低,矿物表面疏水性增强;当捕收剂体系为BHA+OHA+4-MBA的三元组合捕收剂时,白钨矿表面水分子相对浓度最低,表明该三元组合捕收剂间存在协同作用,使矿物表面表现出更强的疏水性。针对某复杂低品位白钨矿进行了浮选试验,结果表明,在BHA浮选白钨矿体系中加入BHA用量11.11%的4-MBA,有效提高了BHA对白钨矿的浮选效果,在保障回收率的同时,BHA用量约降低40%;而BHA用量2.22%的OHA与BHA组合后,白钨矿的浮选回收率约提高20百分点,同时改善了浮选泡沫层。在BHA+OHA+4-MBA的三元组合捕收剂体系中,综合了两种不同的协同作用效果,使钨粗精矿的品位与回收率均达到最佳值。在使用水玻璃与羧甲基纤维素(CMC)组合作为抑制剂,经一粗一扫三精的闭路浮选实验后得到WO_(3)品位为28.55%、WO_(3)回收率为72.04%的钨精矿;与现场使用苯甲羟肟酸单一捕收剂相比,钨精矿的品位与回收率分别提高了3百分点与4百分点左右,捕收剂用量降低了37.5%。在提高白钨矿回收率的同时显著降低了浮选药剂成本,实现了白钨矿的高效回收。

The hydroxamic acid reagents are extremely pervasive in the collector of scheelite flotation.Due to its high price and large dosage,the flotation cost of scheelite is high.To achieve cost−effective and efficient flotation of scheelite,this study proposes a ternary combined collector for scheelite flotation:benzohydroxamic acid(BHA)+R−benzoic acid(4−MBA)+octyl hydroxamic acid(OHA).The synergistic effect of the combined collector in the scheelite flotation system was confirmed by molecular dynamics simulation.Meanwhile,it was further verified that the combined collector has good collection performance for scheelite through actual ore flotation experiments.Molecular dynamics simulation results indicate that as the variety of collector increases,the relative concentration of water molecules on the scheelite(112)surface decreases,enhancing hydrophobicity.The lowest relative concentration of water molecules on the scheelite surface was observed under the ternary combined collector system.This suggests a synergistic effect among the ternary combined collectors,resulting in a stronger hydrophobicity on the mineral surface.The flotation test was conducted on a complex low−grade scheelite ore.The results showed that the addition of 4−MBA at a dosage of 11.11%in the BHA flotation scheelite system effectively improved the flotation effect of BHA on the scheelite ore,while reducing the BHA dosage by approximately 37.5%while ensuring the flotation recovery.When OHA at a dosage of 2.22%was combined with BHA,the flotation recovery of scheelite ore increased by about 20%,and the flotation foam layer was improved.The best flotation effect was exhibited under the ternary combination of BHA+OHA+4−MBA.Using water glass and carboxymethyl cellulose(CMC)as depressants,a closed−circuit flotation test consisting of roughing,scavenging,and three stages of cleaning can obtain scheelite concentrate with a WO_(3) grade of 28.55%and a WO_(3) recovery of 72.04%.Compared to using benzohydroxamic acid as a single collector on site,the grade and recovery of scheelite concentrate increased by approximately 3%and 4%,respectively,while reducing the collector dosage by 37.5%.Therefore,the ternary combined collector can significantly reduce the cost of flotation reagent while improving the recovery of scheelite,and realize the efficient recovery of scheelite.